statistically speaking...

At this point, I'm just plain curious about the statistics of an amniotic false positive. 98-99% accurate is not 100%, and yet when I was googling around like a madwoman trying to find examples of a false positive, I couldn't. Well, not for Down's anyway. I found an example from a scientific journal of a false positive for Turner's (the article was about how the mother aborted based on the amnio results and then upon analysis, the fetus didn't have Turner's after all - and the doctors were wondering why it came up positive...).

After hours of research with the diffuse hydrops, we DID find one example of a case in which the hydrops resolved. Only one, to be true, but I should be able to fine ONE case of a false positive with an amnio if it's not 100% accurate. Right?

So now, here's what I think:

Nearly all the mothers of my Ds groups are really young. And that's because us ladies over 35 are offered the full spectrum of genetic tests (and usually take them) while the younger ones are not. So there are more babies with Ds born to younger mothers than to older ones. The older ones, while more likely to have a baby with Ds, usually abort when they have a positive amnio. The abortion rate is 85-90%.

So there aren't really all that many cases of babies being born of mothers who have an amnio and still choose to keep the baby, and not many tallies of how many might be a false positive.

That's what I think.

Like I said, this is just about my own curiosity at this point and nothing really to do with Rainbow. I'm prepared for her amnio to be correct. I'm not operating on any kind of assumption that she won't have Ds.

But I AM curious about these statistics.